Buttonhole attachment to sewing machines



June l5, 1954 w. DEITCH BUTToNHoLE ATTACHMENT To SEWING MACHINES 2Sheets-Sheet l Filed Oct. l, 1955 QY n June 15, 1954 w. DEITCH 2,681,024

BUTTONHOLE ATTACHMENT TO SEWING MACHINES Filed Oct. l, 1953 2Sheets-Sheet 2 laye/210x.' WML/AM .bf/rc# mf QM fifa/wey Patented June15, 1954 UNITED STATES ,PATENT OFFICE BUTTONHOLE ATTACHMENT TO ySEWINGMACHINES 5 Claims. l

This invention relates to sewing machinery, and in particular it relatesto means associated with a sewing machine for restraining operation ofbutton-hole slitting mechanism upon breakage of the button-hole sewingthread.

In the making of button-holes in `fabrics by well-known forms ofbutton-hole sewing machines, it is customary to stitch the eventualbutton-hole rst and thereafter to slit the fabric within the loop obutton-hole stitching by means of a cutter for the purpose of nnishingthe button-hole.

It has been found in the making of buttonholes in this manner that whilethe sewing thread will frequently break the operation of the mechanismwill nevertheless continue to the end of its predetermined cycle, atwhich time the fabric will be slit by the automatically operable cutterto form the opening in the button-hole stitching which has not beencompleted due to the broken sewing thread. In such cases, it has beenfound extremely difficult, if not impossible, to nish the button-holestitching in a satisfactory manner because the threads of the fabric,having already been severed by the cutter, do not -coact in a normalmanner with the threads 'of the button-hole sewing machine and do notreceive or support the stitching properly.

The above noted conditions have heretofore been given seriousconsideration and means Vhave been provided for preventing completion'of the cycle and operation of the cutter at the vend of thevbutton-hole stitching cycle in the event Ior" sewing thread breakage atany stage in the button-hole sewing operation.

Examples of the contributions of various means for overcoming Athe abovenoted 'conditions are to be *found in the previously granted patents toL. J, Schaeffer, No.'1,025,650; B. M. Krell, No. 1,191,746 and W. T.Leonard, No. 2,645,190, all of which, in `common'withthe presentinvention, are concernedwiththe restraining of movement of a connectinglever from its normal inoperative positionto its operativel position atthe end of a button-'hole sewing cycle.

A primary object of this invention, therefore, is to provide markedsimpliiic'ation 'of the mechanisms disclosed in the aforesaid patentswith equally feiective results.

A further object ofthe invention is to provide .e 'simple means forpreventing operation of the cutter in a button-hole sewing machine,which Lmeans is adapted for 'ready `mounting on AYthe sewing machineframe vand which has continuous `connection withthe'cutter operatingmechanism.

Other .objects and advantages. of rthe invention will becomeapparent inthe course of thevfollowing detaileddescription'taken in connection withthe accompanying drawings, wherein Figure 1 is a fragmentary sideelevational view of a lstandard button-hole sewingmachine, vwith thepresent invention in operative association therewith; and

'Figure 2 is an isometric view of the invention.

Referring now in detailto the drawings, and rst to Figure 1, wherein isillustrated onlysuch structure as is necessary to an understanding ofthe present invention a portion of a standard button-hole sewing machineis indicated at It. 4The forwardly extending arm Il of the machine 'isprovided with a head l2 which houses lthe needle bar I3 and its drivingrmechanism. VThe top rear portion I4 of the arm Il houses the needlereciprocating mechanism and part of 'a stitch control mechanism notessential to an understanding of the present invention, for controllingcertain steps in the stitching process known as barring whereby the endsof the button-hole are finished with a bar stitch.

The stitching thread T is stored in an unwinder `rack (not shown) or anyconventional reel and it extends downwardly through an aperture in thetop of a thread leader post l5. The thread emerges'from the post andpasses through a tension device I6 lprovided with the usual cooperatingdiscs. The tension device Ic is controlled by a rod Il, the purpose ofwhich is knot directly concernedwith the present invention.

From the tension device I6, the thread extends over a thread guide I3and from there to vatension device IS. From the tension device I9, the-thread T`leads toa springtake-up 20 and thence through an eye inatake-up lever 2i 'and vfrom `thereinto a slot in the'face plate of thehead i2. The thread then extends to the eye of the-needle 22.

The needle 22 cooperates rwith a workpiece which is moved by a workpiece clamping device 23. The said device 23 executes a path which is"suitable for stitching the laterally opposed sides and the ends of abutton-hole. Since this 'specific form of workpiece clamping device andits lfunction is not directly concerned with the present invention, itwillnot be further described.

)In the formation of button-holes by machines of the character shown anddisclosed in the patentsabove referred to, the nwork vpiece is cut orslit `within the vstitched loop after the sewing operation, vand to`effect'such cutting a knife 24 is provided which vis clamped Ain va'knife holder 25. The holder is mounted at the lower end of a verticallydisposed bar 26. A downward cutting thrust is imparted to the bar 25 bya knife-bar driving lever 21 which is pivoted intermediate its ends on ahinge screw 28 which is received in a tapped hole in the arm Il. Theforward end of the lever 21 is connected to the bar 26 by means of alink within the head l2 (not shown).

A spring 29 is provided, as is conventional, for biasing the lever 21counter-clockwise with a resulting normal elevated position of thecutting knife 24. At the completion of a button-hole sewing cycle, adriving stroke is imparted to the lever 21 by a driving lever 3B throughan intervening connecting link 3l.

The link 3| is provided with a slot 32 which receives a screw stud 33carried by the adjacent end of the lever 21. rI'he link 3i is pivotallyconnected to the lever 39 by a pivot screw 34. The slot 32 in the link3i provides a lost motion connection between the levers 21 and 353 andis inoperative to effect operation of the button-hole cutting knife 24.

A latch lever 35 is pivotally connected to the link 3| by means of apivot screw 3G. The lever 33 is pivotally connected to the frame of themachine by means of a screw 3l' and the free outer end of the lever isprovided with an elongated slot 38 in which is operatively disposed adriving roller 39 Which is carried by a part of the sewing machine stopmechanism, as is conventional. The latch lever 35 is provided with ashoulder 4G which is engageable with the screw stud 33 for effectingunison operation of the levers 3B and 21 in order to effect a cuttingoperation by the knife 24.

An arm lll extending rearwardly from the latch lever 35 normally restson a, tongue l2 which extends upwardly from a lever catch 23. The catchis pivotally mounted at the end of a xed bracket 4d by means of a pivotscrew bolt 45 and a cooperating nut 1%. The catch 43 is provided with afollower 51 which is yieldably maintained in the path of a cam i8 on thefeed shaft 49.

The latch lever 35 is normally urged into its drive lever connectingposition by means of a spring i) but is not rendered operative unless oruntil the tongue 42 is moved out of the path of the arm 4|, whichnormally is effected near the I tion, it is essential only that it beunderstood that during substantially the entire button-hole sewingcycle, the levers 2l and 39 are uncoupled, and that for only a shortperiod of time at the end of the cycle the said levers are coupledtogether, whereby cutting operation of the knife is held ready duringthe time that the work clamp is positioned beneath same.

The present invention comprises an attachment for the standardbutton-hole sewing machine of the general character above described, andwhich is adapted to retain the latch lever 35 in its inoperativeposition as shown in Figure 1 upon breakage of the sewing thread, eventhough the lever has been automatically released by the tongue 42.

The improved attachment comprises a flat machine I l2. The plate isprovided with a forward .extension 56 which is provided with an aperture51 for reception of an extension on the thread guide i8. The plate isfurther provided with an aperture 58 for the reception of a securingmeans which may be the pivot screw 28 for the lever 21 as is indicatedin Figure 1. The plate may, of course, be provided with additionalsecuring means receiving apertures. A bar 59 is supported on the platefor horizontal sliding movement which may be effected by a bracket 6Bwhich is pivotally secured to the plate by pin 62a, and through whichbracket the bar 59 is freely slidable as is indicated in Figure 2. Therear end of the bar 5i? is provided with an aperture @l (Figure 2) forthe removable reception of a pivot member 62 (Figure 1) for connectionof the bar with the latch lever 35. The bar is bent at right anglesintermediate its ends in the formation of a generally verticallyprojecting arm 63 disposed adjacent the front edge of the plate 55.

A lever arm @t is disposed above the bar 5S in generally parallelrelation thereto, and is pivotally connected to the plate as at c5. Thearm 64 projects substantially beyond the front edge of the plate 55 andis bent at right angles in the formation of an arm portion it extendingat right angles to the plane of plate 55, which angled portion adjacentits free end supports a thread guide which, as shown, is preferably inthe form of a wire loop 61 having a vertical shank 61 adiustablysupported in the arm portion @6 as by a set screw 55. The arm Eli isprovided with a suitably positioned downwardly extending pawl or lug 55Ehaving a forward vertical race l@ engageable with the rear face of theupper end of arm 53 upon breakage of the thread as will hereinaiter bedescribed. Adjacent the rear end of arm 214, provide an inwardlydirected stop pin 12 which extends into an arcuate slot or trackway 'Min plate 55, slot 'Hl being of such length as to limit the upwardmovement of the arm portion 56 during operation of the sewing machine,in order that the disengagement of the knife 2d be not delayed.

With the device which is the subject of this invention, operativelysecured to the button-hole sewing machine as shown in Figure l, thesewing thread T intermediate the spring take-up 2G and the main take-up2 I will extend through the loop 61 and will exert an upward pullthereon as indicated by the arrow in Figure 2. This upward pull on theloop S1 will result in the forward end of the lever arm 5d being swungupwardly about the pivot 65, whereby the lug 69 will be disposed aboveand spaced from the upper free end of the upper end of the vertical arm63 of the bar '59, whereby the latter is free to move rearwardly withthe latch lever 35 for a button-hole cutting operation in a normalstitching cycle wherein the sewing thread remains intact throughout suchcycle,

In other words, the button-hole cutting mecha nism will be free tooperate in its usual manner unless the sewing thread should break duringa button-hole stitching cycle. In the event the sewing thread does breakduring a stitching cycle, the arm Ell which is normally maintained inelevated position by the tension in the sewing thread T, will drop tothe dot-and-dash position shown in Figure 1, whereupon the face 10 onlug t9 will engage the rear face of the vertical arm 63 and therebyprevent rearward movement of the bar 59 in the direction of the arrow inFigure 2 and, consequently, the latch lever will remain in itsinoperative position whereby the cutter mechanism will not function eventhough the entire cycle has been traversed Eby the needle. The spr'mg 5@which normally functions to urge the latch lever 35 into operativeposition will also move the bar 5S when unconstrained by the lug 69.Should the spring 50 normally utilized on button-hole sewing machines betoo weak to move the bar 59 with the latch lever 35, a stronger springmay be substituted therefor.

From the above disclosure, it is to be observed that the attachment asshown in Figure 2 is of very simple construction, and is adapted forready attachment to the frames of existing button-hole sewing machines.It is to be parl ticularly noted that the bar 59 has a pivotalconnection with the latch lever and is bodily movable therewith, wherebyrelatively complex mechanism for effecting connection and disconnectionof a restraining member with and from the latch lever is avoided.

While l have disclosed my invention in accordance with a single specificstructural embodiment thereof, such is to be considered as illustrativeonly, and not restrictive, the scope of the invention being dened in thesub-joined claims.

I claim:

1. An attachment for operative connection with the frame oi abutton-hole stitching machine including a thread carrying needle, abutton-hole cutter, a cutter operating lever, a power operated lever, alost-motion connection between the levers, and a latch lever springurged into interlocking connection of the levers and normally retainedin retractive inoperative position during a stitching cycle by a camcontrolled member, the said attachment comprising a plate, a barslidably supported by the plate and having one end thereof connected tosaid latch lever, an arm pivotally connected adjacent one end thereof tothe plate, said arm being provided with sewing thread engageable meanswhereby the arm is urged upwardly by the normal tension in the thread,and normally spaced means on the bar and arm adapted to be brought intoengagement upon lowering of the arm by gravity in the event or" breakageof the thread for preventing movement of the bar whereby the said latchlever is restrained against movement into operative position forefecting a button-hole cutting operation.

2. The structure according to claim 1, wherein said plate is providedwith a bracket in which said bar is supported for longitudinal movement,and said connection between the bar and latch lever comprises a pivot.

3. The structure according to claim 1, wherein said plate is ofgenerally rectangular form and is provided with an extension having anaperture therein for loosely receiving a projection on the sewingmachine frame and said plate being provided with a second aperture forreceiving a securing screw engageable within the said frame.

4. The structure according to claim 1, wherein said sewing threadengageable means comprises a vertically disposed wire loop having ashank adjustably secured in said arm.

5. The structure according to claim l, wherein said normally spacedmeans comprises a vertical arm on said bar having an upper free enddisposed below said pivoted arm, and a lug on the lower face of saidpivoted arm having a forward vertical face engageable with the rear faceof said vertical arm.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,025,650 Schaeffer May 7, 1912 1,101,746 Krell June 30, 19142,645.190 Leonard July 14, 1953

